基于小波变换圆度误差的检测方法

针对圆度误差在非接触检测过程中噪声对原始信号产生干扰的问题,提出采用小波变换进行采样信号的降噪处理,小波变换具有多分辨率分析的特点,在信号分析处理中能有效区分信号中的噪声,具有良好的去噪能力;讨论了快速小波变换算法及小波阈值降噪法的基本原理和处理实测信号的具体步骤;分析了基于小波变换的最小二乘圆法评定圆度误差的算法,并推导了最小二乘圆的理论模型;运用Matlab小波工具箱并通过试验说明了小波分析处理圆度误差的方法和效果。     

小波变换技术在圆度误差检测中的应用

针对圆度误差非接触检测过程中原始信号包含多频率成分的特点,提出采用小波变换进行信号的滤波处理。介绍了小波理论及快速变换算法的基本原理,讨论了运用小波变换分析处理实测信号的具体步骤。推导了基于小波变换的最小二乘圆法评定圆度误差的理论模型。并通过实验说明了小波变换处理圆度误差的方法和效果。     

基于VB的圆度误差处理

根据圆度误差最小二乘圆法的计算方法和图解原理,利用VB程序实现自动处理数据,求得精确的圆度误差.结合Flash软件实现动态演示,开发了高效、形象、直观的数据处理软件,以提高数据处理的速度、准确度,实现可视化.     

圆度误差的全局评价方法

为了在全局范围正确评价圆度误差,本文借用均匀分布和数论的思想,选择合适数量的初始点,使之均匀分布在设计变量(圆心坐标和半径)可行域之内,同时利用普通的优化迭代算法,得到若干个局部最优点,选择其中使圆度误差最小的一点作为圆度误差评价结果.计算结果表明,介绍的方法可以有效、正确地评价圆度误差.     

圆度误差检测方法现状与展望

介绍了目前的圆度误差检测方法的原理和特点,着重讨论了近年来出现的新型圆度误差检测手段,最后展望了圆度误差检测方法的发展趋势。     

一种用于圆度误差评定的优化算法

一种用于圆度误差评定的优化算法＊刘文文聂恒敬（合肥工业大学精仪系合肥２３０００９）１引言本文提出一种用于圆度误差评定的优化算法,其基本思想是用最小二乘圆的简化模型的线性迭代运算去逼近最小二乘圆精确模型的优化解。与传统算法相比本文算法具有计算速度快、精...     

基于小波变换处理圆度误差的测量方法

由于圆度误差是机械零件及其互换性的重要指标,是产品质量的关键,所以对圆度误差进行测量是十分必要的.本文提出一种利用小波变换的多分辨率分析来评价圆度误差的方法,该方法主要利用小波变换尺度函数的低通特性来对圆度测量数据进行处理,以此来提取圆周轮廓,并在此基础上求出它的半径和圆心坐标,进析求出圆度误差.文中也详细地给出了利用小波变换解决圆度误差测量问题的基本原理及其实现步骤,最后给出实验结果.仿真实验结果表明:该方法可以满足圆度误差的测量要求.     

圆度误差的动态测量

浅述用电感测微仪，光电编码器，Ａ／Ｄ转换板及８０３１单片机实现对园度误差的动态测量，并用最小二乘圆法时行了误差评定     

缺口圆戴面的圆度评定及其最小二乘圆度公式

本文介绍一种计算缺口圆最小二乘半径，以及最小二乘圆度误差的数学方法。     

最小二乘圆法评定圆度误差的程序设计

介绍了用最小二乘圆法评定圆度误差的准则及实现方法,在VC++环境下开发了圆度误差计算评定软件。测试验证表明,程序算法正确,界面直观形象,可直接显示圆度误差值和误差图形。     

基于小波变换软测量技术在大型回转体中的圆度误差方法研究

针对大型回转体圆度误差难以检测的问题,采用非接触式软测量技术以相对测量方法采集大型回转体零件回转面的实测信号,基于小波变换消噪滤波的方法,快速分解提取实测信号中的圆度误差信号,通过圆度误差的评定计算大型回转体的圆度误差。结果表明:该方法能够有效提取大型回转体实测信号中的圆度误差信号,通过实例计算,某2000 mm直径回转体的圆度误差为0.32 mm,该方法为大型回转体圆度误差计算提供一定的理论依据,具有一定的实际应用性。     

Applying particle swarm optimization algorithm to roundness error evaluation based on minimum zone circle

Minimum zone circle (MZC) method and least square circle (LSC) method are two most commonly used methods to evaluate roundness, but only the MZC method complies with the standard definition and can obtain the minimum roundness error value. The determination of the center of MZC is a nonlinear optimization problem which is suitable to be solved by particle swarm optimization (PSO) algorithms. In this paper, the standard PSO algorithm was introduced and theory analysis about the impact of value selection of some important parameters, such as inertia weight ω, on the algorithm’s stability and convergence was carried on so as to provide basis for giving these parameters better values. Furthermore, the superiority of making ω decrease linearly with iterations was verified through a computation experiment in terms of stability and accuracy, compared with the other three cases of ω = 1, 0.5, 0. Based on the analysis, the novel PSO algorithm, with ω decreasing linearly from 0.9 to 0.4 and the LSC center as the initial positions of the particles, is implemented to obtain MZC-based roundness errors of sampling points collected from circular section profiles by a coordinate measuring machine (CMM). By comparing the novel PSO–MZC results with the LSC-based results, it is concluded that the former are a little smaller than the latter, which verifies that the novel PSO algorithm is feasible to calculate roundness error and the fact that a LSC-based one is generally larger than a MZC-based result; the values of the two roundness errors are both related to sample size and increase with an increase in the sample size with a decreasing increment.     

两点法在曲轴圆度误差测量中的应用

采用误差分离技术,将经典三点法演化为两点法,对曲轴轴颈圆度误差进行实时在位精确测量。实现曲轴轴颈圆度误差和工件主轴回转运动误差的有效分离,去除了工件主轴回转运动误差对圆度误差的影响,对系统的测量精度及测量误差做了详细分析。     

A hybrid three-probe method for measuring the roundness error and the spindle error

The three-probe method is the most widely used technique for separating the artifact roundness error from the spindle error, with the superiority available for in situ measurement. For further improving the measurement accuracy of the three-probe method, in this paper, the harmonic measurement errors are investigated analytically and experimentally. To achieve this aim, firstly, according to the transfer matrices W(k), the harmonics are classified into two types: the suppressed harmonics with zero W(k) and the unsuppressed harmonics with no-zero W(k). Then, on one hand, through mathematical deduction, the formulation for determining the suppressed harmonics is derived; on the other hand, the measurement errors to the unsuppressed harmonics are experimentally acquired, and the experimental results demonstrate that the measurement errors to the unsuppressed harmonics are greatly related to the determinant of the transfer matrix |W(k)|, but not rigorously in inverse proportion to |W(k)|. Based on the conclusions drawn from the investigations, a hybrid three-probe method is constructed, where several conventional three-probe measurements are performed for optimizing individual harmonic coefficients. Experiments verify that the hybrid three-probe method is more robust to the error sources than the conventional method.     

Determining the theoretical method error during an on-machine roundness measurement

The analysis of the theoretical method error was conducted for on-machine measurements of roundness profiles based on the assessment of radial variations. The derived mathematical relationships were represented graphically. The absolute and relative theoretical method errors were determined for the assumed initial conditions. Planned further research activities are given.     

VB图解法评定圆度误差探索

用VB图解评定圆度误差,克服手工作图评定圆度误差的繁琐、粗糙性,以及计算法的不可观性。展示评定圆度误差过程,为制造加工、质量鉴定与研究提供精确误差值和可视化平台。     

分数阶小波包时频域的信号去噪新方法

为了提高信号去噪的效果,提出了一种基于分数阶小波包变换(FRWPT)的信号去噪新方法。该方法根据输出信号信噪比的大小,用迭代法寻找分数阶小波包变换的最优分数阶p值,通过分数阶小波包变换将带噪信号映射到最优分数阶小波包时频域内,对变换后的信号进行窄带通滤波,最后通过分数阶小波包逆变换对信号进行重构,实现分数阶小波包时频域内的信号去噪。以带噪Bumps信号和语音信号为例的去噪实验结果表明,采用该方法去噪后的信号信噪比明显提高,在抑制噪声的同时可以有效保持细节信息。     

基于多重小波变换的信号去噪及其在软测量中的应用

化工生产过程中采集到的数据信号通常具有随机性和非平稳性，附加了各种噪声，以至于影响数据建模的拟合效果和泛化性能。本文基于小波分析的特点，提出了一种对信号数据进行多重小波变换阈值去噪的方法。该方法可去除大部分高频随机噪声，提取真实信号，进而提高数据的置信度。将该方法与小波神经网络相结合并应用于丙烯腈聚合反应过程质量指标软测量模型中。仿真结果表明，该方法能有效恢复数据的真实性，提高数据建模的拟合精度与泛化性能。